1) Field of the Invention
The present invention relates to a cartridge transferring robot for use in a library apparatus which stores a large number of cartridges such as magnetic tape cartridges and optical disk cartridges, with the cartridge transferring robot taking the charge of the conveyance of the cartridges among a storage rack, a cartridge entry/exit station and a deck unit within the library apparatus, and further relates to a library apparatus including that cartridge transferring robot.
2) Description of the Related Art
In general, a library apparatus functions as a large-capacity external storage memory, and a storage rack in its locker stores several thousands of cartridges each accommodating, for example, a magnetic tape as a storage medium, and access such as write/read of recording/recorded data is automatically done in relation to the storage medium within each of the cartridges.
Furthermore, in addition to the aforesaid storage rack (storage unit) for storing the cartridges, the library apparatus is equipped with a station [for example, a CAS (Cartridge Access Station), a DEE (Direct Entry/Exit), and an FES (Forced Exit Station)] for carrying out the entry of the cartridges from the external into the apparatus or vice versa, a plurality of magnetic tape decks (which will be referred hereinafter to as decks) for conducting access such as write/read of recording/recorded data with respect to a storage medium (magnetic tape) within a cartridge, and a cartridge transferring robot [automatic transferring robot; which will be referred hereinafter to as an accessor (ACC)] for performing the conveyance of the cartridges among the storage rack, the cartridge entry/exit station and the decks.
In the case of such a library apparatus, on receiving an access demand to one cartridge from a host unit or the like, the accessor moves to the storage rack to search the directing cartridge and then transfers that cartridge up to the deck in a state of gripping or holding it through the use of a hand mechanism, thereby putting it into that deck. Whereupon, the deck processes the storage medium (magnetic tape) within the cartridge. The cartridge discharged from the deck after the completion of the processing is regripped by the hand mechanism of the accessor and transferred up to the storage rack by that accessor to be stored in a given location.
Each of the prior decks is provided with a cartridge delivering and receiving mechanism dedicated thereto, and an accessor inserts a cartridge into the cartridge delivering and receiving mechnaism which in turn, actually inserts or loads the same cartridge into the deck. Further, a cartridge discharged from the deck is handed over through the cartridge delivering and receiving mechanism to the accessor.
In connection with the recent increase in volume of information in computer systems, the fully automatized library apparatus as mentioned above has appeared as a means for storing information in a state of freely allowing the recording/reproduction without the need for the use of an operator, which permits the storage of a large number of cartridges. Whereas, such a library apparatus has been put on the market targeting high end users, and hence, is considerably costly. However, the market for the library apparatus tends to extend toward the middle/low end users in the future, and therefore, the development of a multi-function, low-cost and compact library apparatus for the middle/low end users is of a pressing need, and it is strongly desired to realize such a library apparatus.